Growth of greenhouse gas emissions will slow “substantially” by 2030 as a result of a range of new policies, laws and promises by governments, says a new UN report.

The study picks through climate plans submitted by 189 countries before and after the 2015 Paris Agreement, and determines there is a global will to tackle climate change.

What’s new about this report is that those 189 plans cover nearly 100% of global emissions linked to countries, offering a clearer picture of the challenge ahead.

Emissions from the burning of oil, gas and coal together with changes in land use are expected to grow 16% from 2010-2030, compared with 24% from 1990-2010.

If implemented the world’s climate plans could lead to aggregate global emission levels of 51.4- 57.3 gigatonnes of CO2 equivalent in 2025 and 52.0-59.3 Gt CO2 eq in 2030. That’s a problem, because according to UNEP to avoid 2C of warming, emission levels should not exceed the equivalent of 48 Gt CO2 eq by 2025 and 42 Gt CO2 eq by 2030.

Meanwhile, global per capita emissions are projected to fall 4% by 2025 on 2010 levels. Underpinning those potential declines is a raft of legislation weaving its way through parliaments, adds the UN.

“The [plans] show an increasing trend for introducing national policies and related instruments for low-emission and climate-resilient development,” it reads.

Still, there is a gulf between policy commitments and the steep emissions cuts atmospheric science dictates.

As the chart below demonstrates the 161 climate plans (counting the EU-28 as one bloc) barely make a dent in efforts to avoid the 2C global warming danger zone.

(Pic: UNFCCC)

Factor in the aspirational target at the COP21 Paris summit to avoid warming of 1.5C and the so-called “ambition gap” looks even tougher to meet.

It’s perhaps welcome then that the focus on adaptation – or preparing for the consequences of climate impacts – is also now high on the list of government priorities.

Water, agriculture, biodiversity and health are the four key sectors where countries fear they will face negative consequences linked to warming.

Globally aggregated costs based on the annual loss of GDP range from 1-2% by 2030, 1.8 to 8.6% by 2050 and 9.4% by 2100.

Egypt, for instance, forecasts the Nile flow to decrease 20-30% in next 40 years. Drought, storms and sea level rise also feature on the main concerns of governments, as outlined in the chart below.

This report suggests systems for measuring, reporting and verifying vital climate data like emissions should be standardised to make evaluating progress easier.

“Problems remain in relation to data gaps and the quality of the information… further efforts are needed to increase the capacity of many countries to plan, implement and monitor their climate related actions,” it says.

For example, as a baseline year for emissions some national plans chose 1990, others 2005 while 2000, 2002, 2006, 2007, 2008, 2009, 2010, 2013, 2014 and 2015 made appearances.

Uncertainty also exists on projections of emissions from land use change (known as LULUCF), shipping and aviation.

Estimated aggregate emissions from 2025-2030 can only be presented as a range while ambiguity remains over how countries account for carbon sinks like forests, says the UN.

Equally, glacier-like talks on slowing pollution from planes and ships also means future emissions from these sectors are largely assumed, adding another layer of guesswork for analysts trying to predict the world’s future temperature.